Fotokatalitička razgradnja acetamiprida u rotirajućem fotoreaktoru

master's thesis

• Title (english): Photocatalytic degradation of acetamiprid in a rotating photoreactor
• Author: Kristina Povijač
• Mentor: Vesna Tomašić (mentor)
• Committee member: Vesna Tomašić (predsjednik povjerenstva)
• Committee member: Sandra Babić (član povjerenstva)
• Committee member: Marin Kovačić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-15, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U radu je istražena fotokatalitička razgradnja neonikotinoidnog insekticida acetamiprida u rotacijskom fotoreaktoru uz recirkulaciju reakcijske smjese. Kao vanjski izvor fotoinducirane pobude fotokatalizatora korištene su UV-A lampe snage 15 W, a kao fotokatalizator primijenjen je titanijev dioksid, TiO2. Cilj istraživanja bilo je određivanje reaktivnih kisikovih radikala ključnih za uspješno provođenje fotokatalitičke razgradnje izabrane modelne komponente, a za tu svrhu korišteni su odgovarajući kemijski spojevi, tzv. hvatači koji pokazuju veliku reaktivnost s pojedinim kisikovim i ostalim reaktivnim vrstama. Zaključci o učinkovitosti fotokatalitičke razgradnje doneseni su na temelju određivanja promjene koncentracije modelne komponente kao funkcije vremena ozračivanja. Eksperimentalno dobiveni rezultati tijekom fotokatalitičke razgradnje testirani su na pretpostavljeni reaktorski i kinetički model te su procijenjeni parametri modela. Analizom dobivenih rezultata utvrđeno je da superoksidni anionski radikali te singletni kisik imaju presudnu ulogu u mehanizmu fotokatalitičke razgradnje acetamiprida. U prisutnosti malih koncentracija vodikovog peroksida dolazi do poboljšanja učinkovitosti, što se tumači nastajanjem dodatnih superoksidnih anionskih radikala. U prisutnosti kalijeva persulfata značajno je poboljšana razgradnja acetamiprida što je rezultat nastajanja sulfatnih radikala koji su izuzetno jaki oksidansi. Na temelju dobivenih rezultata izvedene su preporuke za buduća istraživanja s ciljem utvrđivanja uloge reaktivnih kisikovih radikala ključnih za uspješno provođenje fotokatalitičke razgradnje.

Abstract (english)

Photocatalytic degradation of the neonicotinoid insecticide acetamiprid was studied in a rotating photoreactor with recirculation of the reaction mixture. A 15 W UV-A lamps were used as an external source for photoinduced excitation of the photocatalyst, and titanium dioxide was used as the photocatalyst. The aim of the study was to determine the reactive oxygen radicals that are crucial for the successful performance of photocatalytic degradation of the selected model component. For this purpose, scavengers exhibiting high reactivity with individual oxygen and other reactive species were used. Conclusions about the efficiency of photocatalytic decomposition were drawn based on the determination of the change in concentration of the model component as a function of irradiation time. The experimentally obtained results during the photocatalytic degradation were tested on the assumed reactor and kinetic model and the model parameters were estimated. The analysis of the obtained results showed that superoxide anion radicals and singlet oxygen play a crucial role in the photocatalytic degradation mechanism of acetamiprid. In the presence of low concentrations of hydrogen peroxide, the efficiency improves, which is explained by the formation of additional superoxide anion radicals. In the presence of potassium persulfate, the degradation of acetamiprid is significantly improved due to the formation of sulfate radicals, which are extremely strong oxidants. Based on the obtained results, recommendations were made for future research to determine the role of reactive oxygen radicals, which are crucial for the successful performance of photocatalytic degradation.

• Keywords: neonikotinoidi; acetamiprid; heterogena fotokataliza; TiO2; hvatači; reaktivni kisikovi radikali
• Keywords (english): neonicotinoids; acetamiprid; heterogeneous photocatalysis; TiO2; scavenger; reactive oxygen radicals
• Language: croatian
• URN:NBN: urn:nbn:hr:149:285249
• Project: Number: IP-2018-01-8669; Title: Intenzifikacija fotokatalitičkih i katalitičkih procesa za obradu otpadnih voda i otpadnih plinova; Acronym: IN-PhotoCat; Leader: Vesna Tomašić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-04-13 12:33:17